Evaluation of Ultrasound Measurement of Fat Thickness and Ribeye Area, II. Repeatability of Measurements

Data from two feeding trials were used to evaluate repeatability of ultrasound measurements of fat thickness and ribeye area. In each trial, steers were scanned three or four times by one technician. Two beef improvement federation (BIF)-certified technicians with different levels of experience interpreted images from the last scan. Each technician interpreted the image of an individual steer twice on two different days. Repeatability was evaluated as an intra-class correlation. Additional statistics used to evaluate repeatability were the slope and intercepts from a regression analysis, RMSE, and ESD. Ultrasound measurements of fat thickness and ribeye area were repeatable both within and across technicians. The only exception was the across-technician measurements of ribeye area, where an apparent difference in variances of measurements was observed.